Variable spacing mechanism for typewriters



Feb. 21, 1961 R -r 2,972,401

VARIABLE SPACING MECHANISM FOR TYPEWRITERS Filed July 21, 1959 2Sheets-Sheet 1 INVENTOR. R I NA L DO SALTO A TTORNE Y5 R. SALTO Feb. 21,1961 VARIABLE SPACING MECHANISM FOR TYPEWRITERS 2 Sheets-Sheet 2 FiledJuly 21, 1959 INVENTOR. PIA ALDO 55/) L TO BY 2 a A 7'7'Ofi/VEYS UnitedStates Patent VARIABLE SPACING MECHANISM FOR TYPEWRITERS Rinaldo Salto,Ivrea, Italy, assignor to lug. C. Olivetti & C., S.p.A., Ivrea, Italy, acorporation of Italy Filed July 21, 1959, Ser. No. 828,563

Claims priority, application Italy July 26, 1958 13- Claims. (Cl.197-84) This invention relates to variable spacing mechanisms fortypewriters and the like comprising a toothed escapement member urged ina letter-feed direction and normally engaged by movable dog meansagainst said urge, said dog means being mounted for engagement with anddisengagement from said escapement member and for a variable retrogrademovement counter to said direction.

In the known mechanisms of this kind the variable extent of theretrograde movement of the movable dog means is controlled by a set ofselecting members settable immediately upon depression of a selectedkey, whereupon the movable dog means are disengaged under the control ofthe conventional universal bar operable by the type lever just beforestriking the platen. The two different control devices provided to thisend require intricate adjusting means for exactly timing theiroperation.

In a known variable spacing mechanism a selecting member set forcontrollingthe retrograde movement is additionally operable by saiduniversal bar to disengage the movable dog. To this end each selectingmember is operatively associated with an individual arresting member forthe movable dog, whereby undesirable clearances are unavoidable betweena set selective member and its associated arresting member. Furthermore,the selecting members are moved first according to a .first directionfor controlling the retrograde movement and thereupon according to asecond direction for disengaging the movable dog, whereby the mechanismbecomes expensive to be manufactured.

The primary object of the. invention is to provide a variable spacingmechanism of a very reliable operation obviating these disadvantages.

A more specific object of the invention is to provide a variable spacingmechanism wherein no adjusting means are required for timing thedisengagement of the movable dog meanswith respect to its retrogrademovement.

Another object of the invention is to provide efficiently manufacturableescapement member and movable dog means, the latter being formed by aplurality of movable dogs mutually off-set by whole units of spacing.

According to the invention, in a variable spacing mechanism having atoothed escapement member urged in a letter-feed direction, movable dogmeans normally engaged with said escapement member against said urge,and means mounting said movable dog means for engagenrent with anddisengagement from said escapement member and for a variable retrogrademovement counter to said direction, I now provide a set of elementsselectively operable for in a single stroke disengaging said movable dogmeans and entering the path thereof to arrest said retrograde movement.I Further objects, features and advantages of the inventionwill becomeapparent from the following detailed description of two preferredembodiments thereof, taken in conjunction with the accompanyingdrawings, wherein:

Fig. 1 is a partial perspective view of a variable spacing mechanismaccording to a first embodiment of the jpvention incorporated in atypewriter.

' 2,972,401 Patented Feb. 21, 1961 Fig. 2 is a partial view of themechanism of Fig. 1;

Fig. 3 is a right hand sectional view of the mechanism of Fig. 1;

Fig. 4 is a partial perspective view of a variable spacing mechanismaccording to a second embodiment of the invention.

With reference to Fig. 1, the numeral 4 indicates a toothed escapementmember or rack secured to the conventional paper carriage of atypewriter. The rack 4 is formed with teeth spaced apart at a pluralityof three unit intervals of spacing and is impositively urged by a springnot shown in the drawings in a letter-feed direction represented by thearrow 5. The rack 4 is normally engaged against said urge by movable dogmeans formed of a plurality of three movable dogs 6, 7 and 8 mutuallyoflE-set by whole units of spacing, namely one unit of spacing (Fig. 2).

Means are provided for mounting the movable dog means for engagementwith and disengagement from the escapement member 4 and for a variableretrograde movement counter to the direction of the arrow 5. Saidmounting means comprise a stationary shaft 10 coopcrating with a slot 9provided in each one of the movable dogs 6, 7 and 8 and arrangedsubstantially parallel to the rack 4. Furthermore, comprised in saidmounting means is a pin 11 secured to the lower movable dog 8 andengaging a slot 12 for each one of the dogs 6 and 7. Three springs 13individually urge the dogs 6, 7 and 8 to normaliy engage with the rack 4against the impositive urge of its spring and, upon disengagementtherefrom, by rocking about the shaft 10 to variably retrograde counterto the direction of the arrow 5.

The pin 11 enables the dogs 6, 7 and 8 to be simultaneously shiftedparallel to the rack 4, which by engaging a single dog (in Fig. 1 thedog 7), urges all the dogs to abut against the shaft 10 (see Figs. 1 and2). The slots 12 enable the dogs 6, 7 and 8 to be rocked diflferentiallyin order to individually engage the rack 4. In Figs. 1 and 2 the tooth14 of the rack 4 is engaged by the middle dog 7, while the dog 8contacts the rear edge of said tooth 14 and the dog 6 contacts the rearedge of the tooth 15 of the rack 4.

It will be apparent that the rack 4, having its teeth spaced apart threeunit intervals of spacing, as well as the individual dogs 6, 7 and 8,may be efficiently manufactured to support the repeated shocks involved.

According to the invention a set of elements 19 are selectively operablefor in a single stroke disengaging the movable dogs 6, 7 and 8 andentering the path thereof to arrest their retrograde movement. Moreparticularly, each element 19 is formed of the upper projection of alever 20 of a set of adjacent levers fulcrumed on a common pivot 21secured to a plate 22 and is adapted to cooperate with a control edge ofeach one of the movable dogs 6, 7 and 8 as will be hereinafterdescribed. The levers 20 are spaced apart one unit interval of spacing.

The horizontal arm of each lever 20 is connected to an individual lever30 (Fig. 3) fulcrumed on a common pivot 31 secured to the plate 22 andurged counterclockwise by a spring 32. Each lever 30 is in turnconnected by means of a wire link 33 to an individual universal bail 34,35 pivoted on a shaft 36. The universal bails 34 are selectivelyoperable by a number of key-controlled setting members 37.

According to the embodiment of Figs. 1 to 3 the control edge of the dogs6, 7 and 8 comprises in order, in the direction of the arrow 5, astraight guiding portion 16, a reengagement control portion formed of-acut-out slot 17 and an arresting'portion or shoulder 18 projecting withrespect to the guiding portion 16.

The spacing mechanism according'to this embodiment operates as follows;i

3 Upon depression of a key the corresponding setting member 37 (Fig. 3)is shifted leftwards whereby at the end of its forward stroke itsprojection 38 selectively operates one of the universal bails. Theoperated universal bar 34 through the link 33 and the lever 30 rocks itsassociated lever 20 counterclockwise, whose associated projection 19 isthus operable for in a single stroke coopcrating with said guidingportion 16 to bodily rock the movable dogs 6, 7 and 8 about the shaft 10and disengage same from the rack 4, and simultaneously entering the pathof the arresting portion or shoulder 13 thereof to arrest the retrogrademovement after a variable extent.

Upon being disengaged the movable dogs 6, 7 and 8 are bodily shiftedrightwards by their springs 13 and are guided by the projection 19 ofthe rocked lever 26 along the guiding portion 16 of their control edge.

When the slot 17 of the movable dogs 6, 7 and 8 reaches the rocked lever24), the shoulder 18 is arrested by the projection 19 after a retrogrademovement of the movable dogs corresponding to the rocked lever 28 andthe slot 17 enables the movable dogs to reengage the rack 4.

Due to the inertia of the paper carriage the movable dogs reengage therack before the latter has started moving. When the rocked lever 20 isrestored by its spring 32 the rack 4 by the urge of its spring restoresthe movable dogs 6, 7 and 8 leftwards until arrested by the shaft It Itwill be apparent that the travel of the rack 4 in letter-feed directionis arrested by that one of the movable dogs which upon reengaging therack is nearest the forward edge of a tooth thereof. The travel of therack 4 will thus be equal to the retrograde movement of the movable dogsaccording to the position of the rocked lever 29. More particularly, thefour levers 20 of Fig. 1 beginning from the left enable the rack 4 to bemoved through two, three, four and five unitintervals of spacing.

Since the spacing of a lower case character may be different from thespacing of the corresponding upper case character a second projection 39is provided on the setting members 37 which may operate the universalbars 34 when'an upper case character is printed, the shaft 36 beingbodily movable with the conventional type bar segment of the typewriter.

To avoid damage where the movable dogs .6, 7 and 8 are not reengagedbefore the rack 4 starts moving, there is provided a fixed dog 28pivoted on the shaft 10 below the movable dogs 6, 7 and 8. The fixed dog28 .is con trolled by a lever 24 fulcrumed on a pivot 23 of the plate 22and provided with a universal member such as a pin 25 urged by a spring27 to contact the right edge of a slot 26 of each one of the levers 20(Fig. 3). The dog 28is normally kept disengaged from the rack 4 by'thespring 27 which is stronger than the spring 29.

When a lever 20 is rocked counterclockwise, through the pin 25 it rocksthe lever 24 clockwise thus releasing the fixed dog 28 which may engagewith the rack-4 by the urge of the spring 29. The accidental movement ofthe rack 4 before being reengaged by the movable dogs 6, 7 and 8 maythus be arrested after a maximum travel of three unit intervalsofspacing thus avoiding any damage of the spacing mechanism. Whentherocked lever 20 is restored the-spring 27 disengages the fixed 'dog28 whereby the .rack 4remains under the sole control of the 45, 46 and47 being spaced apart one unit interval of spacing. By the urge of anindividual spring 48 the levers 45, 46 and 47 normally contact a bentlug 49 of a universal member or bail 50 fulctumed on the pivot 21 urgedby a spring 51 to contact the horizontal arm of the levers 20.

Upon rocking a lever 20 counterclockwise as described above, the movabledogs 6, 7 and 8 are disengaged from the rack 4 to be retrograded bytheir springs 13 as usual, and the bail 50 is rocked counterclockwise,thus releasing the levers 45, 46 and 47 which now engage the rack 4. Therack 4 will thus be permitted to move in letter-feed direction through asecond variable extent according to the previous retrograde movement ofthe movable dogs until arrested by the shaft 10 by the intermediary ofone of said dogs.

It is desirable for certain kinds of typewritten matter to write thecharacters with slightly increased spacing. To this end the plate 22(Figs. 1, 3 and-4) carrying the pivots 21, 23 and 31, is rockablymounted on two staaway from the shoulder 18 one unit interval ofspacing.

The projections 19 will thus arrest the movable dogs 6, 7 and 8 so as toincrease their retrograde movement a constant extent, namely one unitinterval of spacing.

It will be noted that the pin 31 and the lower arm of the levers 30 arearranged along the rotational axis of the 'pivots 40, whereby the actionof the universal bails 34 on the levers 20 remains unaffected when theplate 22 is rocked.

It'will be'understood that many changes and improvements in the form anddetails of the mechanismillustrated may be made by those skilled in theart without departing from the limits of the invention.

What I claim is:

1. Ina variable spacing mechanism, a toothed escapement member urged ina letter-feed direction, movable dog means normally engaged with saidescapement member against said urge, means mounting said movable dogmeans for engagement with and disengagement from said escapement memberand for a variable retrograde movement counter to said direction, a setof elements selectively operable for in a single stroke disengaging saidmovable dog means and entering the path thereof to arrest saidretrograde movement, and a set of universal bars associated with saidelements, each one of said universal bars being movable for operatingits associated element.

2. In a variable spacing mechanism, a toothed escapement member urged ina letter-feed direction, movable dog means normally engaged with-saidescapement member against said urge, means mounting said movable dogmeans for engagement with and disengagement from said escapement memberand for a variable retrograde movement counter to said direction, a setof levers selectively rockable for in a single stroke -disengaging saidmovable 'dog means and entering the path thereof to arrest saidretrograde movement, and 'a 'set 'of universal 'bars associated withsaid levers, each one of said universal bars being operable for rockingits associated lever.

3. In a variable spacing mechanism, a toothed escapement member urged ina letter-feed direction, movable dog means normally engaged with saidescapement member against said urge, means mounting 'said movable dogmeans for engagement with and disengagement from'said 'escapementrnemberand for a variable retrograde movement counter to said-direction, a set'of elements selectively operable for in a single-stroke disengagingsaid'movable dog means and-entering the 'pa'th'theredf-to ar-rest saidretrograde movement, a common support for mounting said set of elements,and means for moving said support to shift said set counter to' saiddirection in order to increase said retrograde movement a constantextent.

4. In a variable spacing mechanism, a toothed escapement member urged ina letter-feed direction, movable dog means normally engaged with saidescapement member against said urge, said movable dog means comprising aguiding portion and an arresting portion, means mounting said movabledog means, for engagement with and disengagement from said escapementmember and for a variable retrograde movement counter to said direction,a set of elements selectively operable for in a single strokecooperating with said guiding portion to disengage said movable dogmeans and entering the path of said arresting portion to arrest saidretrograde movement, and a set of universal bars associated with saidelements, each one of said universal bars being movable for operatingits associated element.

5. In a variable spacing mechanism, a toothed escapement member urged ina letter-feed direction, movable dog means normally engaged with saidescapement member against said urge, said movable dog means comprising aguiding portion and an arresting portion, means mounting said movabledog means for engagement with and disengagement from said escapementmember and for a retrograde movement according to a variable number ofunit intervals of spacing counter to said direction, and a set ofadjacent levers spaced apart one unit interval of spacing and having aprojection on each lever, said levers being selectively rockable tocause the associated projections to cooperate with said guiding portionfor disengaging said movable dog means and simultaneously to enter thepath of said arresting portion for arresting said retrograde movementafter a number of unit intervals corresponding to the selected lever.

6. In a variable spacing mechanism, an escapement member having teethspaced apart a plurality of unit intervals of spacing and being urged ina letter-feed direction, a plurality of movable dogs normally engagedwith said escapement member against said urge, said movable dogs beingmutually oif-set by whole units of spacing, each movable dog comprisinga guiding portion and an arresting portion, means mounting said movabledogs for engagement with and disengagement from said escapement memberand for a variable simultaneous retrograde movement counter to saiddirection, and a set of levers selectively rockable for in a singlestroke cooperating 'with said guiding portion to disengage said movabledogs and simultaneously entering the path of said arresting portion toarrest said retrograde movement.

7. In a variable spacing mechanism, a toothed escapement memberimpositively urged in a letter-feed direction, a movable dog meansspring urged to normally engage with said escapement member against saidimpositive urge and, upon disengagement therefrom, to variablyretrograde counter to said direction, said movable dog means having acontrol edge comprising, in order in said direction, a straight guidingportion, a reengagement control portion and an arresting portion, meansrockably mounting said movable dog means for engagement with anddisengagement from said escapement member and shiftably mounting saidmovable dog means for said retrograde movement, and a set of elementsselectively operable for in a single stroke engaging said guidingportion to rock said movable dog means and disengage same and enteringthe path of said arresting portion to arrest said retrograde movement,said reengagement control portion enabling said movable dog means toreengage said escapement member when said arresting portion is arrestedby the operated element.

8. In a variable spacing mechanism, an escapement member having teethspaced apart a plurality of unit letter-feed direction, a plurality ofmovable dogs spring urged to normally engage with said escapement memberagainst said impositive urge and, upon disengagement therefrom, tovariably retrograde counter to said direction, each movable dog having acontrol edge comprising, in order in said direction, a straight guidingportion, a cut-out portion and an arresting portion, means rockablymounting said movable dogs for engagement with and disengagement fromsaid escapement member and shiftably mounting said movable dogs for saidretrograde movement, and a set of adjacent levers spaced apart one unitinterval of spacing and having a projection on each lever, said leversbeing selectively rockable to cause the associated projections to engagesaid guiding portion "to rock said movable dogs and disengage same andto enter the path of said arresting portion to arrest said retrogrademovement, said cut-out portion enabling said movable dogs to reengagesaid escapement member when said arresting portion is arrested by theprojection of the rocked lever.

9. In a variable spacing mechanism as defined by claim 8, a normallydisengaged fixed dog for said escapement member, and a universal memberconditionable by said levers upon being rocked for engaging said fixeddog with said escapement member.

10. In a variable spacing mechanism, a toothed escapement member urgedin a letter-feed direction, movable dog means normally engaged with saidescapement member against said urge, means mounting said movable dogmeans for engagement with and disengagement from said escapement memberand for a variable retrograde movement counter to said direction,normally disengaged fixed dog means for said escapement member, a set ofelements selectively operable for in a single forward stroke engagingsaid fixed dog means, disengaging said movable dog means and enteringthe path thereof to arrest said retrograde movement, and in a returnstroke disengaging said fixed dog means, engaging said movable dog meansand leaving said path, and a set of universal bars associated with saidelements, each one of said universal bars being movable for operatingits associated element.

11. In a variable spacing mechanism, an escapement member having teethspaced apart a plurality of unit intervals of spacing and being urgedina letter-feed direction, a plurality of movable dogs normally engagedwith said escapement member against said urge, said movable dogs beingmutually otf-set by whole units of spacing, each movable dog comprisinga guiding portion and an arresting portion, means mounting said movabledogs for engagement with and disengagement from said escapement memberand for a variable simultaneous retrograde movement counter to saiddirection, a plurality of normally disengaged fixed dogs for saidescapement member, said fixed dogs being spaced apart one unit intervalof spacing, a set of levers selectively rockable for in a single strokecooperating with said guiding portion to disengage said movable dogs andsimultaneously entering the path of said arresting portion to arrestsaid retrograde movement, and a universal member conditionable by saidlevers upon being rocked for in a forward stroke engaging said fixeddogs with said escapement member and in a return stroke disengaging saidfixed dogs.

12. In a variable spacing mechanism, an escapement member having teethspaced apart a plurality of unit intervals of spacing and beingimpositively urged in a letter-feed direction, a plurality of movabledogs normally engaged with said escapement member against saidimpositive urge, said movable dogs being mutually ofi-set by whole unitsof spacing, each movable dog comprising a guiding portion and anarresting portion, means mounting said movable dogs for engagement withand disengagement from said escapement member and for a .variintervalsof spacing and being impositively urged in a 15 able simultaneousretrograde movement counter to said 7 direction, a plurality of normallydisengaged fixed dogs for said escapement member, said fixed dogs beingformed of a plurality of adjacent levers spaced apart one unit intervalof spacing and simultaneously rockable for engagement and disengagementwith said escapemcnt memher, a set of selectively rockable adjacentlevers spaced apart one unit interval of spacing and having a projectionon each lever, the levers of said set being selectively rockable tocause the associated projections to cooperate with said guiding portionfor disengaging said movable dogs and simultaneously to enter the pathof said arresting portion to arrest said retrograde movement, and auniversal member conditionable by any lever of said set upon beingrocked for causing the levers of said plurality 8 to alternate with saidmovable dogs in the engagement of said escapement member.

13. In a variable spacing mechanism as defined by claim 12, a commonsupport for mounting said set of levers and said plurality of levers,and means for moving said support to shift said set and said pluralitycounter to said direction to increase said retrograde movement aconstant extent.

References Cited in the file of this patent UNITED STATES PATENTS

